Full name Arystar Krory III, he is a man with split personalities: His soft, kind, and overly-emotional side, and his "battle-mode" side. You can easily tell when he switches between either personality by his expressions. He is very kind looking at one point with his different colored hair down, but when fighting his eyes become evil-looking, veins protrude from his face, making him look like a monster, and his different colored hair sticks up completely. He spent his entire life prior to becoming an Exorcist in a castle and was shunned by the surrounding villagers, who believed he was a vampire because he attacked certain villagers, the way he had attacked them and the fact that he has the stereotypical vampire theme. This is because his teeth were made of Innocence and he was instinctively attacking Akuma, but the villagers did not know that (and, before meeting Allen and Lavi, neither did he). Later, he fell in love with Eliade, not knowing that she was an Akuma. Allen and Lavi (who enjoys teasing Krory in a fight by calling him "Kro-chan", or "Krokins") later come and recruit him to be an exorcist. He is still getting used to the "outside world."

Arystar's Innocence, still unnamed, resides in his teeth, but the strength is in his blood. It grants him a Feral-type ability. When invoked, it gives him great strength, and the ability to drink the blood of akuma, which can allow himself to regenerate and gives him a temporary increase in strength. He is also capable of draining the akuma poison from another person before it can take full effect. However, he is not immune to Akuma poison. Krory's Innocence and body simply break it down (when his body is too weak however, his body cannot fully break down the poison). Krory is also able to remove it from another person by drinking their blood. He can also inoculate his blood on the Akuma, poisoning them and killing them in very few seconds, but this, apparently, weakens him greatly. Taking the commentary of Miranda about the crimson snow that Arystar produced, he named this ability as "Crimson". Arystar is also capable of wrapping blood around his hands to fortify the flesh beneath; this is because his Innocence allows him to manipulate the blood in his body and, to an extent, others' bodies. He can even detach the blood from his body to make it nigh invulnerable and wield his max strength remotely as a winged blood mannequin called "Bloody Krory"; It appears that after the usage of this technique he becomes exhausted, much like the blood inoculation.